No correlation appeared with prostate or colorectal cancers, although the relatively short time frame would have made any change unlikely.

But, while there was a correlation between eating organic foods and lower rates of cancer, it doesn’t necessarily mean one caused the other.

People who choose organic foods are likely to be healthier, wealthier and better educated, all factors known to impact risk of cancer, the study explains.

Researchers note that this is the first study of its kind so the findings need to be confirmed in other studies before organic food can be proposed as a preventive strategy against cancer.

However, past research has found that higher intakes of fruit, vegetables and wholegrains – however they are grown – and lower intakes of processed and red meats can decrease the risk of cancer.

As previous studies with this group had shown people who choose organically grown products tend to have higher income, higher levels of education and healthier diets.

So the researchers adjusted for these factors.

They also made adjustments for other factors that could affect the outcome, such as age, sex, the month the participants were included in the program, marital status, physical activity, smoking status, alcohol intake, family history of cancer, body mass index, height, energy intake, and the intake of dietary fibre and also red and processed meat.

For women (who made up 78 per cent of the study group), they also adjusted for the number of children they had, oral contraception use, postmenopausal status and use of hormonal treatment for menopause.

In 2015, the International Agency for Research on Cancer classified some pesticides as “probably carcinogenic to humans”.

This means there is limited evidence of a link between pesticide use and cancer in humans, but sufficient evidence of a link between pesticide use and cancer in experimental animal studies.